In a case of a pouch for drinks with a straw hole, the pouch is automatically manufactured by a bag making machine, so that substantial contrivance is required for sealing the straw hole from inside of the pouch.
In one of the methods known currently, a seal tape 22 is set inside the pouch in the horizontal direction as shown in FIG. 5 so that the seal tape 22 covers the straw hole 21 from inside thereof, and a circumference of the straw hole 21 indicated by the sign W in FIG. 7 and portions 24, 24a crossing the side seals 23, 23a in FIG. 5 and FIG. 6 respectively are heat-sealed.
Because of this feature, inside the pouch 20, a portion other than the heat-sealed area of the seal tape 22 is separated from the pouch 20 toward the content therein as shown in FIGS. 6 and 7, and this separated portion of the tape 22a sometimes cause troubles in filling content in the bag. Further the thickness of the sections where side seals 24, 24a are applied to the seal tape 22 is larger by the thickness of the seal tape 22 than that side seals 23 and 23a, so that sometimes pin holes may be generated due to a fault in heat sealing, and if the temperature for heat sealing is raised to address generating the pin holes, excessive heat is applied to other side seals 23 and 23a, which in turn may generate pin holes there.
In addition, as the thickness of the pouch 20 in the section where the seal tape 22 is applied becomes larger as compared to those in other areas thereof, and when these pouches 20 are set in a magazine of an automatic filling machine or the like, the pouches 20 are not well aligned, which may easily cause troubles.
Further, the content is easily stuck to and deposited on the tape 22a, and fungus or bacteria deposited on the tape 22a may cause contamination of the content.